KR20110043198A

KR20110043198A - Key input device for removing gost key

Info

Publication number: KR20110043198A
Application number: KR1020090100212A
Authority: KR
Inventors: 임준열
Original assignee: 엘지에릭슨 주식회사
Priority date: 2009-10-21
Filing date: 2009-10-21
Publication date: 2011-04-27

Abstract

The present invention relates to a keyboard device capable of recognizing a plurality of key inputs, and more particularly to a keyboard device having a configuration in which ghost key generation is eliminated. A keyboard capable of simultaneously inputting a plurality of keys, comprising: a scan line, a signal line, a switch located at an intersection of each scan line and each signal line, and including a resistor, and sequentially applying scan signals to each scan line A key scan signal input unit and a key input signal output unit for receiving an output signal from each signal line, wherein the scan line is connected to the key scan signal input unit to transmit a scan signal, and the signal line is connected to the key input signal output unit. It provides a keyboard that is connected and delivers a scan signal.

Description

New KEY INPUT DEVICE FOR REMOVING GOST KEY}

The present invention relates to a keyboard device capable of recognizing a plurality of key inputs, and more particularly to a keyboard device having a configuration for eliminating ghost key generation.

In personal computers, notebook computers, desktop computers, etc., the user can use the keyboard as an input device of the system. The keyboard refers to a device for inputting a program or data by pressing a key of a letter desired by a user of an electronic product such as a computer, and may include a touch screen type keyboard as well as a general keypad type keyboard. In input using the keyboard, it is important to know exactly which key the user has entered.

Typically, a keyboard has a key matrix structure including a plurality of keys disposed at each intersection of a plurality of rows and columns and a plurality of switches disposed corresponding to the keys. Each switch is closed when the key of the corresponding position is pressed to electrically connect the rows and columns of the position where the switch is placed. A key scan method may be a general method of recognizing a key input of a user from a keyboard having a key matrix structure. The key scan method sequentially applies a key scan signal for each column (or each row) on the key matrix, and then checks the signal state of each row (or each column) after a predetermined delay time has passed. It is a method of determining whether a key disposed at an intersection of columns is pressed. That is, when a key arranged at a predetermined position is pressed, if a key scan signal is applied to the corresponding column (or row) of the key, the key scan signal corresponds to the key pressed through the corresponding column (or row). Via a switch (closed), the key is applied to the row (or column) to which it belongs so that signals are detected from that row (or column). By combining the applied key scan signal and the output signal, it is possible to determine which key is currently pressed.

In some cases, the user may need to enter several keys simultaneously. For example, a command can be entered into a system with a combination of keys, such as pressing the CTRL, SHIFT, and ALT keys simultaneously. However, in the key recognition method according to the above-described key scanning method, while pressing two or more keys belonging to the same row (or column) on the key matrix, the key belonging to the same column (or row) as one of the keys already pressed is pressed. If another key is pressed further, a phenomenon in which an unpressed key is pressed may be wrongly recognized, which is called a ghost key phenomenon. Therefore, in order to prevent false key recognition, each system has taken various measures. For example, in some computer systems, when the above-mentioned ghost key phenomenon may occur, the keyboard may simply ignore all the keys currently input and send a signal to the central processing unit indicating that an error has occurred. The CPU receiving this error code may output a warning sound. In addition, many other computer systems use additional complex hardware devices and / or software to come up with measures to prevent false key recognition due to ghost key generation.

However, there are problems that all of these existing measures significantly impair the performance of the computer system or require complicated and expensive additional devices.

The present invention provides a keyboard apparatus having a new structure which can structurally prevent the generation of ghost keys and can accurately recognize a plurality of input keys simultaneously.

According to one aspect of the invention, a matrix structure comprising N x M switches in which N scan lines are cross-aligned with M signal lines and which connect N scan lines with M signal lines, where N and M are positive. Wherein each of the switches comprises a resistor, and each of the switches may configure or block an electrical path between a corresponding scan line of the scan lines and a corresponding signal line of the signal lines; A key scan signal input unit connected to the scan lines and sequentially applying scan signals to the scan lines; And a key input signal output unit connected to the signal lines to receive an output signal from the signal lines.

According to one embodiment of the invention, each of the switches provides a keyboard that connects the corresponding scan line with the corresponding signal line near an intersection where the corresponding scan line intersects with the corresponding signal line.

According to an embodiment of the present invention, there is provided a keyboard further comprising a signal selection unit disposed between a key input signal output unit and signal lines.

According to one embodiment of the invention, the signal selector provides a keyboard, comprising switches and resistors.

According to one embodiment of the invention, each of the switches of the signal selector is provided with a keyboard, consisting of a SPDT switch, a transistor or a CPLD element.

According to one embodiment of the invention, the signal selector provides a keyboard, implemented by software.

The keyboard device according to the present invention can prevent the ghost key phenomenon without the complicated and expensive separate hardware or software device by simply changing the structure. Therefore, there is an advantage that it is possible to prevent the ghost key phenomenon and improve the accuracy of key recognition at low cost without increasing the load on the system.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following, when it is determined that there is a risk of unnecessarily obscuring the gist of the present invention, a detailed description of already known functions and configurations will be omitted. In addition, it should be understood that the following description relates to one embodiment of the present invention, but the present invention is not limited thereto.

1 illustrates a schematic configuration of a computer system according to an embodiment of the present invention.

As shown, the computer system 100 includes a keyboard device 110 capable of receiving a user's key input, a central processing unit 120 controlling each component of the computer system 100, and an input signal. It includes a display device 130 for showing to. Keyboard device 110 also includes keyboard controller 112, keyboard buffer 114, and key matrix structure 116. Although not specifically illustrated, the key matrix structure 116 in the keyboard device 110 includes a plurality of keys (and switches corresponding to each key) disposed at the intersection of each row and column on a matrix composed of lines of a plurality of rows and columns. And a key scan signal driver for sequentially applying scan signals to each column line of the plurality of keys, and a key input signal output unit for receiving output signals from each row line of the plurality of keys. A detailed configuration of such a key matrix 116 will be described later with reference to FIG. 2.

In relation to the operation of the computer system 100, when a user presses a key at a predetermined position, the code value of the input key may be transmitted to the keyboard controller 112. According to an embodiment of the present invention, the keyboard controller 112 may store the received code value in the keyboard buffer 114 and request an interrupt for key input from the central processing unit 120. The central processing unit 120 may read the code value from the keyboard buffer 114 and display it on the display device 130.

2 is a diagram illustrating in detail the key matrix structure 116 shown in FIG. 1 in accordance with an embodiment of the present invention.

In general, a key matrix structure includes N x M switches in which N scan lines are cross-aligned with M signal lines and connect N scan lines with M signal lines, where N and M are positive integers, Each of the switches includes a resistor, and each of the switches may configure or interrupt an electrical path between a corresponding scan line of the scan lines and a corresponding signal line of the signal lines. As shown, the key matrix structure 116 has a matrix arrangement of four columns arranged in such a way that the scan lines 206a-206d and four rows, ie, the signal lines 208a-208d, intersect each other. . One switch 210a-210p is disposed at the intersection of each scan line 206a-206d and each signal line 208a-208d. Each of the switches connects the corresponding scan line with the corresponding signal line near an intersection where the corresponding scan line intersects with the corresponding signal line. Each switch 210a-210p corresponds to one key, respectively. The on / off of the switches 210a-210p can connect or disconnect the electrical path between the corresponding scan lines 206a-206d and the signal lines 208a-208d. Typically, each switch 210a-210p is off and the scan lines 206a-206d and signal lines 208a-208d that cross each other are electrically isolated. However, when a predetermined keypad is pressed by the user, the switches 210a-210p at positions corresponding to the keypad are turned on and thus corresponding scan lines 206a-206d and signal lines 208a- intersecting with each other. 208d) is electrically connected. Each of the signal lines 208a-208d is arranged to intersect the scan lines 206a-206d so as to be connected to the resistors 212a-212d each of which is grounded outside the area where the keypad is located. Resistor 212a-212d is a pull-down resistor that allows ground voltage to be applied to key input signal output 204 when there is no signal on corresponding signal line 208a-208d. Each of the switches 210a-210p may include a resistor R. When the predetermined scan line 206a-206d and the predetermined signal line 208a-208d cross each other and a scan signal is applied to the corresponding scan line, the scan signal is passed through the corresponding switch 210a-210p to the signal line ( 208a-208d, the voltage of the applied signal can be significantly lowered while passing through the resistors R of the switches 210a-210p. As shown in FIG. 2, four scan lines and four signal lines are shown, but it should be understood that the present invention is not limited thereto.

The key matrix structure 116 also includes a key scan signal input 202. The key scan signal input unit 202 may be connected to the scan lines to sequentially apply the scan signals to the respective scan lines 206a-206d, and may repeat the sequential application of the scan signals at predetermined intervals. Therefore, each scan line 206a-206d can be sequentially activated by applying the scan signal from the key scan signal input unit 202.

The key matrix structure 116 further includes a key input signal output 204. The key input signal output section 204 may be connected to a signal line to receive an output signal from each signal line 208a-208d. As described above, when a scan signal is sequentially applied to each scan line 206a-206d by the key scan signal input unit 202, the key input signal output unit 204 is applied when a predetermined time elapses after the scan signal is applied. Signals from signal lines 208a-208d can be sensed. After the key scan signal input unit 202 applies a scan signal to a predetermined scan line and the key input signal output unit 204 detects a signal on the predetermined signal line, the key scan signal input unit 202 is disposed at an intersection point of the corresponding scan line and the signal line. When the keypad is pressed (ie, the switch corresponding to the corresponding key is closed to electrically connect the scan lines and the signal lines that cross each other). In this case, the key input signal output unit 204 may report the detected signal to the keyboard controller 112.

Looking at the operation of the key matrix structure 116 in more detail, for example, when the keypad disposed at the position of the switch 210a is pressed, the scan line 206a and the signal line 208a are electrically connected by the switch 210a. Can be connected to each other. In this state, when a scan signal from the key scan signal input unit 202 is applied to the scan line 206a, the scan signal is inputted through the scan line 206a, the switch 210a, the resistor R, and the signal line 208a. The signal output unit 204 may be transferred. Accordingly, the key input signal output unit 204 may detect the input of the corresponding keypad.

FIG. 3 is a diagram illustrating a signal flow in the key matrix structure 116 shown in FIG. 2 when three adjacent keys are pressed simultaneously, in which a ghost key phenomenon may occur in a conventional keyboard device. Since the functions of each component have already been described with reference to FIG. 2, duplicate descriptions will be omitted herein.

As shown, the three adjacent switches 210f, 210g and 210k are closed respectively. That is, although not shown in FIG. 3, the respective keys A, B, and C disposed at positions corresponding to each of the switches 210f, 210g, and 210k are simultaneously pressed. As shown, switch 210f and 210g are located on scan lines 206b and 206c adjacent to each other on the same signal line 208b. Switch 210g and switch 210k are located on adjacent signal lines 208b and 208c on the same scan line 206c.

In this case, when a scan signal is applied from the key scan signal output unit 202 to the scan line 206b, the applied high signal may flow along the scan line 206b and flow through the switch 210f. At this time, it should be noted that the Low signal is applied to the scan lines other than the scan line 206b. The signal applied to scan line 206b flows through signal R 208b disposed on switch 210f as it passes through switch 210f. In this case, the signal passing through the switch 210f may flow to the key input signal output unit 204 and flow to the opposite side through the corresponding signal line 208b to pass through the switch 210g corresponding to the key B. The signal passing through the switch 210g flows through the corresponding resistor R, and the signal passing through the resistor R of the switch 210g passes through the key scan signal output unit 202 on the scan line 206c to which the low signal is being applied. Can flow towards. However, since the low signal is currently applied to the scan line 206c with the switch 210k, and the switch 210k has a resistance R, the signal passing through the switch 210g flows toward the opposite switch 210k. I can't.

Therefore, when the key scan signal input unit 202 applies a voltage signal to the scan line 206b, the key input signal output unit 204 can detect the high signal from the signal line 208b, but the signal line ( The high signal cannot be detected from 208c. This is because the voltage signal applied to the scan line 206b cannot flow to the signal line 208c due to the resistance added to the switch as described above. Accordingly, the key input signal output unit 204 may detect that the switch 210f (ie, the corresponding key A) is pressed, and the switch 210j (ie, the corresponding key) is pressed down. You may not make the mistake of misrecognizing that something is wrong.

In the case of a keyboard device in which a resistor is not conventionally disposed in each switch, assuming that three adjacent keys are simultaneously pressed as described above, the signal line 208b flows along the scan line 206b and passes through the switch 210f. The signal passing sequentially through the switch 210g, the scan line 206c, and the switch 210k could be detected by the key input signal output unit 204. Thus, the key input signal output section 204 is based on the combination of the scan signal applied to the scan line 206b and the signal sensed at the signal line 208c, so that the switch 210j (ie, correspondingly) is not actually pressed. Key) is wrongly detected as being pressed (ghost key). However, as described above, according to the present invention, such an error can be prevented.

4 is a diagram illustrating the key matrix structure 116 illustrated in FIG. 1 in detail according to another embodiment of the present invention. Here, the detailed description of the same parts as those described with reference to FIG. 2 will be omitted, and a description will be given focusing on the differences.

As shown in FIG. 4, the key matrix structure 116 may further include a signal selector 310 disposed between the key input signal output and the signal line. The signal selector 310 has switches 302a-302d and resistors 304a-304d. It should be noted that the switches 302a-302d are shown in single pole double throw (SPDT) and the resistors 304a-304d are shown in a pull up manner, but the invention is not so limited.

Switches 302a-302d and resistors 304a-304d respectively correspond to one signal line 208a-208d. The corresponding switches 302a-302d can be turned on / off by the voltage signal applied to the signal lines 208a-208d. That is, when the voltage signal is low, the switches 208a-208d are turned on, and a ground voltage, that is, a low voltage is applied to the key input signal output unit 204. Conversely, when the voltage signal is High, the switches 208a-208d are turned off, and the pull-up voltage of the resistors 304a-304d, that is, the High voltage, is applied to the key input signal output unit 204. This may be useful when the user of the signal selector 310 inputs a large number of keys at the same time. For example, when running a particular game based online or offline, the user may need to enter a significant number of keys at the same time. When many keys are pressed simultaneously, the high signal applied by the key scan signal input unit 202 may flow to the key input signal output unit 204 after passing through many resistors. In this case, a voltage drop due to a resistance may occur. For example, when the user inputs 10 keys simultaneously, the voltage applied to the key input signal output unit 204 is V '= VxR' / (R '+ R2), and R' = R / 10, so that R2 = In the case of R, V '= V / 11. In this case, since the voltage drops about 11 times than when one key is input, the high signal is recognized by the key input signal output unit 204 even though the high signal is applied to the scan lines 206a-d. You may not be able to.

In order to prevent the high value from being recognized due to the voltage drop, the present invention may optionally add a signal selector 310 including switches 302a-302d and resistors 304a-304d. The signal selector 310 including the switches 302a-302d and the resistors 304a-304d drives the switches 302a-302d according to the signal of the signal line 208, so that the number of resistors through which the voltage signal has passed. Irrespective of this, since a certain high signal is inputted to the key input signal output unit 204, the key input signal output unit 204 may detect the input of the corresponding keypad more accurately.

For example, when the user inputs the "A" key, when the high signal is applied from the key scan signal input unit 202 to the scan line 210a, the scan signal is scanned line 206a, switch 210a, When the resistor R and the signal line 208a are transferred to the signal selector 310 and the scan signal is connected to the control signal of the switch 302a, the switch 302a connected to the ground in the normal state is set to OPEN. Connected. Accordingly, the high signal of the pull-up resistor 304a is transmitted to the key input signal output unit 204 so that the key input signal output unit 204 may sense the input of the corresponding keypad A. FIG. In the present invention, the switch of the signal selection unit 310 is not limited to this, but may be composed of elements such as SPDT switch, transistor, CPLD, even if implemented by software that can perform the same function of the present invention It may be included in the range of.

Although the present invention has been described in detail with reference to exemplary embodiments, those skilled in the art to which the present invention pertains can make various modifications without departing from the scope of the present invention. I will understand. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

FIG. 2 illustrates in detail the key matrix structure shown in FIG. 1 in accordance with an embodiment of the present invention. FIG.

Fig. 3 shows the signal flow in the key matrix structure shown in Fig. 2 when three adjacent keys are pressed at the same time.

FIG. 4 illustrates in detail the key matrix structure shown in FIG. 1 in accordance with another embodiment of the present invention. FIG.

100: computer system

112: keyboard controller

114: keyboard buffer

116: key matrix

120: central processing unit

130: display device

Claims

In the keyboard,

A matrix structure comprising N x M switches in which N scan lines are intersected with M signal lines and connecting the N scan lines with the M signal lines, where N and M are positive integers and the switches Each of the switches comprises a resistor, each of the switches being capable of constructing or blocking an electrical path between a corresponding scan line of the scan lines and a corresponding signal line of the signal lines;

A key scan signal input unit connected to the scan lines and sequentially applying scan signals to the scan lines; And

A key input signal output unit connected to the signal lines to receive an output signal from the signal lines

Keyboard that includes.

The method of claim 1,

Each of the switches connects the corresponding scan line with the corresponding signal line near an intersection where the corresponding scan line intersects with the corresponding signal line.

The method of claim 1,

And a signal selector disposed between the key input signal output unit and the signal lines.

The method of claim 3,

And the signal selector comprises switches and resistors.

The method of claim 4, wherein

Wherein each of the switches of the signal selector is comprised of an SPDT switch, a transistor, or a CPLD element.

The method of claim 3,

And the signal selector is implemented by software.